Grumman G164 accident near Riverdale, California, July 28, 2009
On July 28, 2009 at about 6:00 pm local time, a Grumman G164, registered N8741H, was substantially damaged in an accident during maneuvering (low-alt flying) near Riverdale, California. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The partial loss of engine power due to the failure of the engine's supercharger-blower.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 28, 2009 · about 6:00 pm local time
- Place
- Riverdale, California · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Grumman G164 A · all G164s on the register
- Registration
- N8741H · no longer on the register · serial 1508
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
During a spray pass the pilot detected a "hot smell," which prompted him to pull up out of the field to check his engine gauges. As everything appeared normal the pilot returned to the field to continue spraying operations. Upon re-entering the field the pilot reported that "…the engine changed sound." After pulling up out of the field a second time the pilot revealed that the engine began to slow down, followed by the emission of smoke from the exhaust system. The pilot made a successful forced landing in the field he was spraying; however, due to the wet field conditions it nosed over on its back, which resulted in substantial damage to the airplane. A post accident teardown examination revealed that the engine had failed as a result of a supercharger-blower failure. It also revealed that foreign object material was detected in the engine; however, it could not be determined if this was causal to the engine failure. The manufacturer recommends an overhaul time of between 600 to 1,000 hours for engines operated in aerial application operations. At the time of the accident the engine had accumulated a total of 835.27 hours since its most recent major overhaul.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Powerplant sys/comp malf/fail during maneuvering (low-alt flying) defining event
- Loss of engine power (partial) during maneuvering (low-alt flying)
- Off-field or emergency landing during emergency descent
- Roll over during post (impact)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng supercharger › Failure
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instructor: powered-lift; instrument: airplane
- Flight time: 14,601 hours in all; 50 in the last 90 days; 40 in the last 30 days; 14,201 as pilot in command
- Last flight review: March 1, 2009
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: sngl
- Injury: minor injuries
The aircraft
- Airframe total time: 9,280 hours
- Last inspection: 100-hour inspection, July 3, 2009; 43 hours since
- Maximum gross weight: 7,550 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney R-1340 (piston); 0 hours total
- Operator: Kennys Crop Dusting Inc.
The flight
- Departed from: Rasin City CA at 5:30 pm
- Destination: Riverdale CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 310° at 5 knots
- Visibility: 10 statute miles
- Sky: scat at 15,000 ft
- Temperature: 91°F (33°C), dew point 54°F (12°C)
- Altimeter: 29.80 inHg
- Observation at 5:56 pm from NLC, 6 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N8741H the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.